Shielding of tube support for furnace tube panels



Jan. 5, 1965 H. LIESSENBERG 3,164,137

SHIELDING OF TUBE SUPPORT FOR FURNACE TUBE PANELS Filed Jul 5, 1962 2 Sheets-Sheet 1 INVENTOR Henry Liessenberg ma KM ATTORNEY 2 Sheets-Sheet 2 5 5 5 9 ii {I} w l Ii R n I 0 mm/ 3 M N y 0 w w an H Jan. 5, 1965 H. LIESSENBERG sarswmc OF TUBE. SUPPORT FOR FURNACE TUBE PANELS Filed July 5, 1962 FIE: m a

ATTORNEY United States Patent 3,164,137 SHIELDING 0F TUBE S'UPfORT FGR FURNACE TUEE PANELS Henry Liessenberg, Windsor, Conan, assignor to Combustion Engineering, Inc., Windsor, Come, a corporation of Delaware Filed July 5, 1962, Ser. No. 207,548 1 Claim. (Cl. 122-510) This invention relates to a support and shielding or protecting means therefore for furnace tube panels.

In many boiler installations being constructed today use is made of vapor generating or heating platen or panel sections which extend down into the upper portion of the furnace, which sections are made up of sinuous, internested tubes lying in a plane parallel to the furnace side walls. As boilers become larger, the panel sections extending down into the furnace increase in size accordingly, and the problem of supporting these large panels in an economical and reliable manner is more difficult.

The temperature existing in the upper portion of the furnace is in the range of 2500 F.-3000 F. Any tubes and support means therefore positioned in the furnace absorbs heat both by convection and radiation. and thus must be constructed in such a manner that they can withstand extremely high temperature conditions without failing.

It is an object of this invention to provide a support and shielding means therefore for furnace tube panel which will be able to withstand the extremely high temperatures they are exposed to without failure.

Other objects and advantages will be more fully understood from the specification hereinafter following by reference to the accompanying drawings wherein:

FIG. 1 is a schematic elevational section through a steam generator utilizing my tube panel supports and the shielding means therefore;

FIG. 2 is an enlarged horizontal cross-section of one of the tube panel supports and shielding means shown in FIG. 1, taken on line 2-2 of FIGS. 1 or 3;

FIG. 3 is an elevational view of one of the tube panel supports shown in FIG. 1, taken on line 3-3 of FIG. 2; and

FIG. 4 is a cross-sectional elevation of the tube panel support and shielding means taken on line 4-4 of FIG. 3.

Looking now to FIG. 1 numeral designates a steam generator having a furnace 12. Fuel and air are introduced into the furnace through burner 14 and is burned therein. The hot combustion gases pass up through the furnace and then downwardly through the gas pass 16 in the direction indicated by the arrows.

Positioned within the upper portion of the furnace is a platen or dividing Wall panel 20. This panel is made up of a plurality of sinuous, internested tubes which are supplied with Water from header 22. After absorbing heat, both by convection and radiation, these tubes discharge a mixture of steam and water into outlet header 24.

The panel 20 is supported by fluid cooled supporting tubes 28, 30, 32 and 34 from one side, and by means of four corresponding tubes (not shown) on the other side of the panel. Supporting means 26 permits the weight of the tubes within panel 20 to rest upon and thus be supported by the supporting tubes 28, 30, 32 and 34. A plurality of these supporting means 26 are vertically spaced throughout the panel section. The supporting tubes should be fluid cooled, and thus as illustrated, they are supplied with a cooling fluid from supply headers 40 and 42, the fluid passing therethrough being collected in outlet header 44. All of the supporting tubes can be suitably supported from the boiler framework by means of hangers 46.

Looking now to FIGS. 2, 3 and 4, the details of the supporting means 26 can be seen. Supporting tubes 28 and 30 are positioned on one side of the panel tubes 20, and supporting tubes 36 and 38 are positioned on the other side. Supporting lugs 50 and 52 are suitably secured to two of the panel tubes 20 on either side thereof, as best shown in FIG. 4. Shelf members 54 and 56 which are welded to supporting tube 28, 36, and 30, 38, respectively are positioned such that the lugs 50 and 52 rest thereupon. In this manner the weight of the panel tubes 20 is carried by the four supporting tubes.

As mentioned earlier, the tube panels positioned within the furnace are becoming larger and larger in size, and it is not uncommon for such panels to exceed 50,000 pounds weight. For thi reason, the supporting lugs 50 and 52, must be of substantial size due to the great weight that must be carried. Because of the increased size of these members it is not possible to adequately cool them by means of fluid passing through the panel tubes and the supporting tubes, and thus without some means of shielding or protecting them they would soon become overheated and fail. To prevent this from happening, shieldmembers 58, 60, and 62 are suitably positioned and secured to the supporting tubes such that the extremely hot combustion gases will not come into direct cont-act with the supporting lugs, nor will such supporting members be exposed to radiant heat from the furnace. Shielding member 58 is welded along opposite edges to supporting tubes 28 and 39. Shielding member 60 is correspondingly welded along opposite edges to supporting tubes 36 and 38. The flat spacer tie 62 is positioned beneath the supporting lugs 50 and 52, and is welded to all four of the supporting tubes. Thi member 62 prevents hot combustion gases from flowing up between the panel tubes 20 and the adjacent supporting tubes. The shielding means 58 and 60 prevents the hot combustion gases from passing between the supporting tubes into contact with the supporting lugs. Since all of the gases are flowing in an upward direction, and since the source of burning fuel is beneath the tube panels, there is no necessity for protecting the supporting means from above. The shielding means 58, 60 and 62 are made of a thin enough material, and are in good heat exchange contact relationship with the fluid cooled support tubes, such that they will not become overheated to the extent that they will be burned or corroded away. The tubes, support members, and shielding means should be made of a suitable ferritic material such as carbon steel, carbon molybdenum, or chromemolybdenum steel, which is capable of withstanding relatively high temperatures.

Although my shielding and tube support arrangement has been shown and described in conjunction with a vapor generating panel positioned in the upper portion of the furnace, it should be apparent that other uses are also possible. For example, it could be used in conjunction within vapor heating or vapor generating panels or platens positioned either in the upper portion of the furnace or in the rear gas pass. I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes as fall within the scope of the appended claim.

What I claim is:

In combination a furnace means to produce hot combustion gases in said furnace, a roof and side walls for said furnace, a heat exchanger positioned in the upper portion of said furnace, said heat exchanger comprising a plurality of vertically spaced, parallel tube means; support structure for the heat exchanger, said support structure including first, second, third and fourth fluidcooled vertical tube means that are supported adjacent their upper ends and which extend from the roof of said furnace to a point below said heat exchanger, said first and second vertical tube means being on one side of the heat exchanger, and said third and fourth vertical tube means being on the other side of said heat exchanger, first and second support means secured to said vertically spaced fluid-cooled tube means on opposite side thereof, third support means secured to said first and second vertical tube means, fourth support means secured to said third and fourth vertical tube means, said first and second support means resting on top of and being supported by said third and fourth support means, respectively; first shielding means secured between said first and second vertical tube means, second shielding means secured between said third and fourth vertical tube means, third shielding means secured to said first, second,'third and fourth vertical tube means below said first and second support means; said first, second, and third shielding means being positioned such that they, in conjunction with the third and fourth support means and all of the vertical tube means,

4 substantialiy enclose the first and second support means on the bottom and ail four sides, thereby preventing said first and second support means from being directly exposed to the flowing hot combustion gases and from radiant heat Within the furnace.

References Cited in the file of this patent UNITED STATES PATENTS 2,834,327 Banker May 13, 1953 2,859,737 Banker Nov. 11, 1958 2,884,911 Iankowski May 5, 1959 2,923,279 Schmidli Feb. 2, 1960 FOREIGN PATENTS 536,138 Great Britain of 1941 883,125 Great Britain Nov. 22, 1961 885,315 Great Britain Dec. 28, 1961 

